A flexible non-precious metal Fe-N/C catalyst for highly efficient oxygen reduction reaction.

A novel, flexible non-precious-metal oxygen reduction reaction catalyst is fabricated by direct pyrolysis of carbon cloth decorated with an iron-coordinated aniline and pyrrole copolymer. The resultant Fe-N/C manifests superior activity, long-term stability in alkaline media and comparable activity in acidic electrolyte. The precursor carbon cloth modified with aniline and pyrrole copolymer provides high densities of carbon, nitrogen and iron-doping sites, which generates a great many active sites. Compared to the Pt/C catalyst, Fe-N/C pyrolyzed at 850 °C (Fe-N/C-850) shows excellent activity with onset and half-wave potentials of 17 mV and -174 mV in 0.1 M KOH, which are more activated than an iron-free catalyst (-29 mV and -235 mV) and comparable to those of Pt/C (28 mV and -237 mV) with the same loading. The electrocatalysis and reaction kinetics results demonstrate that Fe-N/C-850 will be a promising catalyst at low cost for applications in fuel cells.